Transmission mechanism having selectively driven output shafts



March 10, 1953 c. c. HUMBERT ET AL TRANSMISSION MECHANISM HAVINGSELECTIVELY DRIVEN OUTPUT SHAFTS 2 SHEETS-SHEET 1 Filed May 3, 1951 EIFINVENTORS Char/es C. Humberf BY Pau/ A. Wards/l W 1 WALL,

A TTORNE Y Patented Mar. 10, 1953 TRANSMISSION MECHANISM -HAVING SE-LECTIVELY DRIVEN OUTPUT-SHAFTS Charles C. Humbert and Paul lti chardWardell,

, Toledo, Ohio Application May 3, 1951, Serial No. 224,296

2 Claims. (01. 74-665) This invention relates to transmission mechanismsbut particularly to a mechanism of this character having a single inputshaft and a pluralityof output shafts.

An object is to produce a new and improved transmission mechanism unitequipped with a single input shaft and a pair of output shafts and acontrol device enabling one or the other of the output shafts to beselectively driven.

Another object is to produce a transmission mechanism of the abovecharacter having the novel features of construction, arrangement andoperation hereinafter described, and for purposes of illustration butnot of limitation, an embodiment of the invention is shown on theaccompanying drawings, in which Figure 1 is a side elevation of thetransmission mechanism unit which is shown operatively connected to anelectric motor, a fragment of which is disclosed;

Figure 2 is an end elevation of the transmission mechanism unit, certainof the gears being shown by broken lines;

Figure 3 is a vertical sectional elevation taken substantially on theline 3-3 of Figure 2; and

Figure 4 is a transverse sectional view substantially on the line 4-4 ofFigure 2.

The illustrated embodiment of the invention comprises a transmissionmechanism unit indicated generally at I, which is connected to be drivenby an electric motor 2. In this instance, the motor is spaced from thetransmission I by a series of sleeves 3 through which extend stud bo1ts4, the ends of which may be screwed into tapped holes in the housing ofthe transmission unit. In this instance, the motor armature shaft 6constitutes the input shaft for the transmission mechanism and as shown,it extends through a boss 1 in the transmission housing, a suitablebushing being provided as a bearing for same. The unit I has a housingmade up of a pair of flanged sections 8 which are held together by aseries of bolt and nut assemblies 9 extending through the flanges. Thisprovides a closed lubricant-receiving housing which contains themechanism hereinafter described.

Keyed to the input shaft 6 adjacent the boss I is a pinion In which isat all times in mesh with a large gear H keyed to a countershaft I2, theends of which rotate in bearing sleeves carried by bosses l3 formed inthe end walls of the housing sections. Also keyed to the countershaft 12adjacent the gear H is an elongate pinion M which is at all times inmesh with a relatively large gear 15, the diameter of which is of thesame size elongate sleeve [6 which is mounted upon the input shaft 6 butis free to rotate relatively theretogas well as toshift axially thereon.Integral with the opposite end of the sleeve [6 is a pinion I1 andbetween thepinion l1 and gear I5is an annular groove J8 which isstraddled by a yoke I9 carried by an arm 20 which extends perpendicularto the axis of the sleeve l6. Connected to the upper end of the arm 29and extending at right-angles thereto is a rod 2| which extends throughan aperture in an end wall of the housing and carries asolenoidrarmature 22 at its outer end which is movable within thesolenoid 23.

Encircling the rod 2| is a helically coiled spring 24, one end of whichbears againstthearm 2|] and the opposite endagainst the inner wall ofthe housing. Thus, it will be apparent that normally the spring 24 holdsthe gear l5 and pinion I! in the left-hand position shown by full lineson Figure 3. Upon energizing the solenoid 23, the gear [5 and pinion I!are shifted to the right but in either of the positions, the gear l5remains in mesh with the pinion $4, the latter being sufiicientlyelongate to aiford the desired later-a1 shifting movement Withoutbecoming disengaged. It will be noted that the free end portion of theinput shaft 6 bears in the sleeve carried by a boss 25 oppositelyarranged to the boss I so that the shaft 6 is supported in opposite endwalls of the housing.

The axially shiftable pinion I! is adapted to mesh either with the gear26 or a gear 21 keyed respectively to output shafts 28 and 29 arrangedin parallel relation on opposite sides of the input shaft 6 andsupported by bearings carried by bosses 30 formed in the adjacent endwall of the housing. The gears 26 and 21 are the same diameter as thegears I l and I5 and these gears are spaced axially from each other, thegear 26 being spaced inwardly within the housing from the gear 21.However, the spacing of the gears is such that the pinion I! can beshifted to mesh with one or the other. Normally, when the solenoid 23 isdeenergized, the pinion meshes with the gear 26. However, uponenergizing the solenoid 23, the pinion H is shifted into mesh with thegear 21. The arrangement is such that the gears 26 and 21 are driven inthe same direction. Manifestly due to the gear reduction, the rotationalspeed of the gears 26 and 21 will be but a fraction of that of the inputshaft 6.

From the above description, it will be apparent that we have produced anexceedingly simple and eflicient transmission mechanism by which, from asingle input shaft, one or another of the output shafts may be drivenselectively at a greatly reduced rotational speed. Although atransmission of this character may be used in a variety of places, itcan be advantageously used for the operation of a hospital bed forselectively raising and/or lowering the foot and head end sectionszofthe bed. The reverse ope.

eration can be simply achieved byemploying a reversible electric motor.

It is to be understood that numerous changesin details of construction,arrangernent and; op eration may be effected without departing; from,

the spirit of the invention especially as defined in the appendedclaims.

What We claim is:

1. Transmission comprising a driversh-aft, a.

pinion fixed to said drive shaft, a countershaft spaced laterally fromand in parallel relation to said drive shaft, a relatively large gearfixed to saidcountershaft andimeshing with saidpinion, a relatively longpinion fixed to saidcountershaft, a relatively large driven gear freetoro tate and slide axially on saiddrive shaft, a pin-- ion coaxial andrigidiwith said driven, gear andsimilarly rotatable and slidablefreely-'- on said drive shaft, said driven gear meshing at all timeswith said relatively long pinion but beingshiftable parallely thereto, apair of output shiftable pinion in mesh with one of said last;

gears.

2. Transmission comprising a drive shaft, a pinion fixed to said driveshaft, a countershaft spaced laterally from and in parallel relation tosaid drive shaft, a relatively large gear fixed to said countershaft andmeshing with said pinion, a relatively long pinion fixed to saidcountershaft, a relatively large driven gear free to rotate; and slideaxiallyon said drive; shaft, a pinion coaxial and rigid with said drivengear and similarly rotatable and slidable freely on said drive shaft,said driven gear meshing at all timesgwith said; relatively long pinionbut being shiftable. parallely thereto, a pair of output shafts arrangedrespectively on opposite sides of saiddriveshaft, gears of substantiallythe same REFERENCES-CITED Ighe following references are of record in thefile of this patent:

U I ED ST ES P TE S Number, Name Date 7,225,202: Ahleet: 211.. o May 8,19.17 2;,1,39 ,5,4,8- Gent Feb.r6, 1940 2gl9,0,924; Joy Feb. 20, 19402,;3frh2fl ly Gentry July 25, 1944 2,543,564 Bakewell;, Feb. 27, 1951.5,5A

Koob June 5, 1951

